[Ifeffit] Give me some advices

wang.kefan at gmail.com wang.kefan at gmail.com
Mon Dec 17 20:35:25 CST 2007


Hi  Leandro
Thank you for your helpful advices. The title should be change to "Please
give me some advices" , and I am sorry for this error.

*The attached .prj file can be opened by Athena rightly by changing the
download file's extend name .bin  to .prj, if someone else want to join our
discuss.*

Then go to our topics:

The QDs samples were prepared by MBE and XAFS measurements, as you guessed,
were performed at a synchrotron facility in fluorescence mode. Since the
Si/Ge intermixing happened frequently during growth, there is certainly Si
in so-called Ge quantum dots(QDs, or nanocrystal). However, now I am very
caring for if the GeOx in the QDs. The XAFS spectra show that there may be
GeOx in the Ge QDs, but since the QDs were covered *in situ* by a 15nm Si
cap layer the oxidizing process of QDs by air should not happen. This
inconsistency between XAFS and experiments is the real reason for that I
want to extract the truth from strict softwae analysis.

1, I have the bulk Ge and diluted SiGe standard spectra, but they do not
resemble with these spectra as you mentioned. I am sure that the QDs is a
combination of Ge and Si elements, and am not clear if the O exists. The
growth temperature is beyond 500oC, and annealing was performed from
550-800oC(all temperature uncalibrated with +/- 50oC ). The amorphous
Ge seems to be impossible, but can not exclude it. *In situ* RHEED also can
not tell me if the deposited Ge is crystallizing.

2, If I truncate the k to 10 A-1, the fit result is accepted or not?


Kefan
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